Objective ques and ans on thermodynamic cycle-Rankine cycle is

Jan 11 • General • 27115 Views • 7 Comments on Objective ques and ans on thermodynamic cycle-Rankine cycle is

1. Rankine cycle efficiency of a good steam power plant may be in the range of

(a) 15 to 20%
(b) 35 to 45%
(c) 70 to 80%
(d) 90 to 95% .
Ans b
2. Rankine cycle operating on low pressure limit of p1 and high pressure limit of p2
(a) has higher thermal efficiency than the Carnot cycle operating between same pressure limits
(b) has lower thermal efficiency than Carnot cycle operating between same pressure limits
(c) has same thermal efficiency as Carnot cycle operating between same pressure limits
(d) may be more or less depending upon the magnitudes of p1 and p2.
Ans. a
3. Rankine efficiency of a steam power plant
(a) improves in summer as compared to that in winter
(b) improves in winter as compared to that in summer
(c) is unaffected by climatic conditions
(d) none of the above.
Ans. b
4. Rankine cycle comprises of
(a) two isentropic processes and two constant volume processes
(b) two isentropic processes and two constant pressure processes
(c) two isothermal processes and two constant pressure processes
(d) none of the above.
Ans. b
5. In Rankine cycle the work output from the turbine is given by
(a) change of internal energy between inlet and outlet
(b) change of enthalpy between inlet and outlet
(c) change of entropy between inlet and outlet
(d) change of temperature between inlet and outlet.
Ans. b
6. Regenerative heating i.e., bleeding steam to reheat feed water to boiler
(a) decreases thermal efficiency of the cycle
(b) increases thermal efficiency of the cycle
(c) does not affect thermal efficiency of the cycle
(d) may increase or decrease thermal efficiency of the cycle depending upon the point of extraction of steam.
Ans. b
7. Regenerative cycle thermal efficiency
(a) is always greater than simple Rankine thermal efficiency
(b) is greater than simple Rankine cycle thermal efficiency only when steam is bled at particular pressure
(c) is same as simple Rankine cycle thermal efficiency
(d) is always less than simple Rankine cycle thermal efficiency.
Ans. a
8. In a regenerative feed heating cycle, the optimum value of the fraction of steam extracted for feed heating
(a) decreases with increase in Rankine cycle efficiency
(b) increases with increase in Rankine cycle efficiency
(c) is unaffected by increase in Rankine cycle efficiency
(d) none of the above.
Ans. b
9. In a regenerative feed heating cycle, the greatest economy is affected
(a) when steam is extracted from only one suitable point of steam turbine
(b) when steam is extracted from several places in different stages of steam turbine
(c) when steam is extracted only from the last stage of steam turbine
(d) when steam is extracted only from the first stage of steam turbine.
Ans. b
10. The maximum percentage gain in Regenerative feed heating cycle thermal efficiency
(a) increases with number of feed heaters increasing
(b) decreases with number of feed heaters increasing
(c) remains same unaffected by number of feed heaters
(d) none of the above.
Ans. a

11. Why Entropy decreases with increase in temperature?

Ans. ds=dQ/T Entropy is inversely proportional to the temperature so, as temp. Increases, entropy decreases.

12. Why different types of sound are produced in different bikes, though they run on SI Engines?

Ans.Engine specifications are different in different manufactures like as Bore Diameter (CC), Ignition timing. Also the exhaust passage takes more responsible for sound.

13. How much Watt means 1Hp?

Ans.746.2 Watt

14. Explain Bicycle Rear Wheel Sprocket working?

Ans.Rear wheel sprocket works under the principle of ratchet and pawl.

15. Definition of Octane Number and Cetane Number?

Ans.     Octane No.- Octane number is defined as the percentage, by volume, of iso octane in the mixture of iso octane and h-heptane. It is the measure of rating of SI engine.Cetane No.- Cetane number is defined as the percentage, by volume, of n-cetane in the mixture of n-cetane and alpha methyl naphthalene. It is the measure of rating of CI engine.

16.Which Mechanism is used in Automobile gearing System?

Ans.Differential mechanism

17. When Crude Oil is Heated, Which Hydro Carbon comes first?

Ans. Natural gas (Gasoline)… at 20 Celsius

18.How to calculate Bearing number ti Diameter of the inner and outer?

Ans.Divide the shaft diameter size by 5, it will give last two digit of the bearing no. and according to type of load we have to choose the type of bearing and that will give prior number of the bearing.

19. The Fatigue life of a part can be improved by?

Ans. Improving the surface finish by Polishing & providing residual stress by Shot peening.

20.What happens if gasoline is used in a Diesel Engine, Siesel Engine will work?

Ans.No, It will not work, as the Compression ratio of Petrol engine is 6 to 10 & that of Diesel engine is 15 to 22. Thus on such high compression, gasoline gets highly compressed & it may blast.

21. Poissons Ratio is Higher in, Rubber/Steel/Wood?

Ans. When a material is compressed in one direction, it usuallytends to expand in the other two directions perpendicular tothe direction of compression. This phenomenon is called thePoisson effect. Poisson’s ratio is a measure of the Poisson effect.

For rubber = 0.5

For steel = 0.288

For wood < 0.2

Thus Poisson’s ratio is higher in RUBBER.

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7 Responses to Objective ques and ans on thermodynamic cycle-Rankine cycle is

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    Note: The trip could be started and finished at Sapa or Lao Cai Railway Station,
    according to your wishes. Net nieuw gebouwd, allemaal een eigen kamer met balkon met uitzicht op de bergen. Between the 11th and 18th centuries, Nanyue expanded to the south conquering the kingdom of Champa
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  2. KRISHNA KUMAR.C says:
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    SPECIFIC STEAM CONSUMPTION OF RANKINE CYCLE CAN BE REDUCED BY

    Reply
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  4. sakshi chaudhary says:
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    here is the collection of questions and answers related to the thermodynamics cycle and its very helpful for students for getting knowledge about the topic……

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  5. Ankita Prajapati says:
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    I am sure they can gain required knowledge about ‘Thermodynamic’ which will surely benefit them at the time of interview for mechanical students…

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  6. saurabh singh says:
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    I Think this article provides us with basic information regarding Thermodynamic Cycle.And it would really benefit students of mechanical branch .

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  7. Siddhant Tripathi says:
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    Theoretical objective FAQs for the Thermodynamic Cycle.

    Reply

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